Grinding, polishing, and buffing machine



Aug. 6, 1929- c. G. JOHNSON GRINDING; POLISHING, AND BUFFING MACHINEFiled April 15, 1926 5 Sheets-Sheet Qwuwytoc C. G. JOHNSON POLISHING,

Aug, 6,: 192 9.

GRINDING, AND BUFFING MACHINE Filed April'l5, 1926 3 Sheets-Sheet Aug.6, 1929. J HN N 1,723,622

GRINDING, POLISHING, AND BUFFING MAGHTNE Filed April 15. 1926' 3Sheets-Sheet 5 Patented Aug. 6, 1929. 15 V UNITED STATES CHARLES G.JOHNSON, OF BRIDGEPORT, CONNECTICUT.

GRINDING, POLISHING, AND BUFFING MACHINE.

Application filed April 15, 1926. Serial No. 102,194.

This invention relates to machines for grinding, polishing or bailing,and particularly to a machine of this type in which the work to beground or polished is mounted on a movable support which isreciprocatcd. back and forth to move the work across the surface of thewheel during the grinding, polisl'iing, or butting operation.Considerable diiliculty has been experienced in prep erly grinding orpolishing articles which have a surface which varies and is not ontirelyin a single plane. For instance, in piano construction there is veryoften a metal bar used which is flattened on one side and this bar maybe of such a shape that a portion of this flattened side may be indifferent parallel planes or in planes in clined to each other. Thisarticle is mentioned merely as an example as, of course, this machine isnot limited to use on this kind of an article.

It is an object of the invention to provide a. grinding,- polishing orbutting machine which will evenly grind or polish the flattened side ofsuch articles as above mentioned or similar articles, and which willautomatically shift the article as it is passed by the abrasive surfaceof the grinding or polishing Wheel so that the immediate portion of thesurface being ground or polished is automatically positioned relative tothe surface of the wheel to maintain the desired contour for thissurface. s

It is also an object of the invention to provide a machine of thischaracter with a floating work support which is reciprocable past theabrasive wheel, and which l' as means coast-ing with other means mountedon the bed of the machine for changing the height of the work support orits angular relation to the surface of the wheel during these movements.

It is a further object of the invention to provide means forautomatically shifting the abrasive wheel back and forth longitudinallyof its axis during the working operation so as to give more uniform wearto the surface of the wheel and to maintain this surface for a longertime in the shape desired.

It is a still further object of the invention to provide an improvedautomatic control means for reciprocating the work support.

With the foregoing and other objects in view, I have devised theconstruction illustrated in the accompanying drawings forming a partofthis specification, similar reference characters being employedthroughout the various figures to indicate corresponding elements. Inthese drawings,

Fig. 1 is a side elevation of the machine.

Fig. 2 is a top plan view with the grinding, polishing or abrasive wheelremoved and with a portion of the bed broken away to more clearly showthe construction.

Fig. 3 is a rear end elevation looking from the right of Fig. 1. i

Fig. l is a top plan view of the work support showing a piece of workcomprising an irregular bar mounted thereon.

Fig. 5 is a longitudinal section thereof substantially on line 55 ofFig. t.

Fig. 6 is an end view of the work support in Figs. 4t and 5 on asomewhat enlarged scale, and

Fig. 7 is a transverse section thereof.

The machine as illustrated comprises av base or bed 10 supported bysuitable legs 11 and on which base the various mechanisms are mounted.Mounted on the top of the base is an upright bracket 12 carrying spacedbearings 13 for a shaft 14.- carrying the abrasive wheel 15. This wheelmay be a grinding wheel, polishing wheel or a butting wheel as desired,and ordinarily the working surface is the periphery thereof. Between thebearings 13 there is a pulley 16 over which any suitable belt from apulley not shown, operated from any suitable source of power, will runfor driving the shaft and the wheel. The bearings 13 are preferablyadjustable vertically to adjust; ing the shaft and wheel. For thispurpose they are mounted in blocks 17 guided in guideways 18 in thebracket, and adjusting screws 19 are connected to these blocks and passthrough a cap 20 on the top of the bracket. The shaft- 14 is alsomounted for longitudinal or axial reciprocation in the bearings 13 togive a back and forth sidewise movement to the work wheel, as indicatedin dotted lines in Fig. 1, so that a greater portion of the surface ofthe wheel will be employed for the working operation and also to keepthis working surface in good condition for a greater length of time,especially in grinding work which is relatively narrow and has atendency to wear a groove in the surface. During the grinding operationthe shaft and wheel are continuously given this reoiprocatory movementautomatically from the driving mechanism.

Mounted at one end of the base is a bracket 21 carrying a short shaftwith a drive pulley 22 arranged to be driven from any suitable source ofpower, not shown, by means of a belt. This shaft carries a pinion 23meshing with a gear 24 carried on a shaft 25. This shaft carries acylinder 26 provided with a cam groove 27. There is a bracket 28 securedat the outer end of the bracket 12 to which is pivoted at 29 a lever 30,and this lever carries a roller 31 running in the cam groove 27. At itsupper end the lever has tapered guideways 32 for a fork 33, this forkbeing provided with an elongated slot 34 through which extends a bolt35. Vith this means the fork may be adjusted up or down to conform toadjustment of the shaft 14 andclamped in adjusted positions by the bolt35. The sides of the fork extend on opposite sides of the shaft 14, andon this shaft within the fork is socured a collar 36 having an annulargroove 37. The fork carries adjustable studs 38 having enlarged heads orrollers 39 running in the groove 37. It will, therefore, be apparentthat as the shaft rotates and with it the cam cylinder 26 the lever willbe rocked about its pivot, and through the fork 33 and the collar 36will shift the shaft 14 and the working wheel 15 back and forth in adirection extending longitudinally of this shaft.

Extending transversely of the base or bed under the wheel 15, is areciprocating table or slide 40. This table has inclined side walls 41cooperating with similar tapered guides 42 in the base, and in operationthis table is reoiprocated back and forth under the abrasive wheel.Mounted on this table so as to reciprocate therewith is my improvedfloating work support. In the form shown on the drawings this supportcomprises a substantially flat plate or block 43 of the required lengthto support the work to be operated upon, and it is mounted on upwardlyextending bolts or studs 44 on the slide 40. These studs extend throughopenings in the support but the openings are sufliciently larger thanthe studs to allow for rocking movements of the plate. The plate is alsomounted on springs 45 about the studs 44 beneath the plate so that theplate is normally supported by these springs to hold the work carriedthereby against the surface of the wheel, but it may yield downwardly ifrequired The upward movement of the plate is limited by means of screws46 in the upper'ends of the studs.

In the drawings, and especially in Figs. 4 to 7. I have shown mounted onthis work support a piece of work 47 comprising a bar of an irregularshape such as the bar in the sounding board of a piano over which thewires are stretched. These bars are bent to various shapes and areusually substantially half round in cross section or are llaltened atone side 48. They also usually have a number of holes all) therethrough.This bar is mounted on the support 43 with the flattened side up, asthis is the side which is to be ground or polished. These bars veryoften are not only curved in a horizontal plane, as shown in Fig. 4, butthey are also often curved in a vertical plane, as shown in Fig. 5, andin addition may be twisted somewhat, as shown in Figs. (3 and 7. It maybe mounted on the support; -13 by suitable pins 50 extending into theopenings 49. and the higher parts may rest on V-shapcd supports 51.

It will be obvious that if the surface of such an article as this is tolve ground or polished uniformly it should be present-ed to the surfaceof the work wheel in various positions, that is, at various heights fromthe bed and also in various angular posi I secure this effect byproviding cams on the support 43 cooperating with rollers car .l by thebed of the machine, and arrangement illustrated these cams com barsmounted on the top of the pl. e 43 along the opposite side edgesthereof, and the top surfaces of these bars are given shapes dependingon the shape of the bar 47 to be polished. Thus adjacent the oppositeends of this bar, for 'tistance, where these ends are lu sld above t-llGplate as shown in Fig. 5. the top of the cam bars will be'corresrmndiugly raised and they will be lower in the center while. ifaportion of the surface of the work is not parallel with the support thecam on one side may be lo er than the cam on the other side so as torock or tip the plate 43. as shown in Fig. 7, to bring the surface ofthe work parallel with the surface of the rork wheel. The cams 52 coactwith rollers 53 which are mounted on levers and so arranged that as thetable -10 and the work holder 43 are rcciprocaled back and forth theserollers 53 will run along the tops of the cam bars 52 and will raise orlower the plate or give it a rocking movement, as shown in Fi 6 and 7.to properly present the flattened side 48 of the bar 47 to tl e surfaceof the wheel 15 and with a un' rm pressure, so that the surface of thisflat side will be uniformly polished or gound, and the liability ofgrinding oll one portion more than another because of the irregula'arrangement of this surface will be obviated.

The lever 54 is pivoted at 56 on a bracket 57 mounted on the bracket 12,and at its opposite end has a linger or extension 53 connected by meansof a spring with a hook Sll llll

Ill-3 carried by the bracket 12. An adjustable stop 01 mounted in thebracket with its lower end above the lever and acts as a stop to limitthe movement ofthe lever under the action of the spring. The lQ/V. 55 ispivoted at 62 in a bracket- 03 on the bed 10. Extending upwardly andoutwardly from this bracket is an man 64: carrying a spring connected tothe outer end of the lover. Th bracket also carries an adjustable stop66 arrangedto engage the top of the lever to limit its movement underthe act-ion of the spring. It will be apparent from an inspection ofFigs. 1, and 4 to 7 that the plate or work support 43 is mounted forsulreztantially universal. movement, or that is, what I call a floatingwork support as it may move up or down or have rocking movements, andthe positions both as to height above the table and its angular relationto the abrasive wheel are controlled by the rollers 53 coacting with thetop surfaces of the cam bars 52. The pressure of the work against thesurface of the wheel is controlled by the s n-inns 4.5, 59 and 65. Forbest results the rollers 53 should be located substantially on thevertical central line of the wheel 15.

As the table 40 may be of considerable length there may be extensionsfor the guides 4), beyond the sides of the base 10. For this purposebrackets 67 may be secured to the opposite sides of the bed and haveguides similar to the guides 42. The table is reciprocatcd automaticallyduring the grindin or polishing operation. I have shown improved meansfor giving the table this reciprocating movement. Secured to the underside of the table and extending; throughout substantially the entirelength thereof there is a rack (38 meshing with a gear 69 on a shaft 70beneath the bed. This shaft has an enlargement 71 on which is a sleeve72 arranged to turn thereon, and keyed to this sleeve, as shown at 73,.is a bevel ear 74L. This bevel gear meshes with an idling bevel gear 7mounted on a shaft 7 G and this ,e'ea r in turn meshes with a bevel gear7 7 on the shaft 25, either keyed to this shaft or pinned, as shown at78. Between the gear and shaft is a sleeve 79 carrying a series of teeth80 adapted to mesh with teeth 81 in a block 82. The other end of thisblock has teeth 83 directed in the opposite direction and adapted tomesh with teeth 841 on the sleeve 72. The block 82 is mounted 011 asliding shaft 82 having driving engagement with the shaft 70 at alltimes so that as the block 82 is rotated it will rotate the shaft 70 andthe gear 69 carried thereby. The block 82 is mounted so as to be shiftedto engage either the teeth 80 on the sleeve 79 or the t eth 84; on thesleeve 72, and as the slee es 7 9 and 72 are rotated in oppositedirections it will be obvious that the gear 69 will be rotated inopposite directions depending on with which sleeve the block 82 is inengagement. The block is shifted by means of a fork 85 running in agroove 80 in the block. This fork is carried on a block 87 mounted on ashiftable rod 88. This rod mounted in bearings 89 and carries stopcollars 90 arranged to engage the hearings to limitthe lateral movementsof the rod. The block87 is connected to a lever 91 piv oted to the baseat 92. The end of the lever has a sliding engagment with a circularelement 91 carried by the block 87. This lever is connected by a link 93with a bell rank 9% pivoted to the base at 95. The other arm of thisbell crank is connected by link 96 to a shiftable bar 97 which carries arack 98. This bar is mounted to slide in suitable bearings 99, and stopcollars 100 limit the movements of this bar. The rack 98 meshes with agear 101 011 a shaft 102 mounted in suitable bearings 011 the under sideof the base. A hand lever 103 is mounted on the shaft by means of whichthe same may be turned to rotate the gear 101. This shaft 102 alsocarries an arm 10 1 projecting upardly through a slot in the base 10 inthe path of movement of dogs or lugs 10h carried by the table 40. Thereis only one of these dogs shown on the drawing, but it will beunderstood there will be a similar dog adjacent the other end of thetable to engage the opposite side of the arm 104 and shift the clutchmechanism to reverse the movement of the table. This means for recinocating the table is especially adapted for this kind of a machinewhere a relative ly long table is used. It will be obvious that the gearand rack drive 0869 may be used with practically any length of tabledesired as its operation not dependent on the length of the table andtables of different lengths may be used on this machine without changingthe reciprocating mechanism and the reversing mechanism therefor.

It is thought the operation of this mechanism for shifting the tablewill be obvious. If the table is moving imwardly, as viewed in Fig. 52,the dog 100 will engage the arm 10% and swing it upwardly to shift thebar 97 downwardly. This movement acting through the bell crank 94 andlever 91 will shift the block 82 from engagement with the teeth 80 onsleeve 79 into engagement with the teeth 8 1 on sleeve 72 and willreverse the movement of the table. Of course, when the table reaches theend of this reverse movement the other dog will engage the arm 1041 andswing the clutch mechanism back into engagement with the sleeve 79 andso on. The dogs or tripping block 100 are adjust-ably mounted on thetable so that they nmy be shifted to vary the point at which thereversing mechanism will be tripped.

It will be apparent from the foregoing description that with my improvedwork support the surfaces of an irregular piece of work may be properlyand uniformly presented to the surface of the wheel to secure thedesired uniform operation thereon throughout the entire surface to beworked. The lateral reciprocatory movement of the wheel will utilizesubstantially the entire working surface thereof and preventwearing ofgrooves in the surface, so that it Wlll be maintained in grinding orpolishing condition for a longer time without requiring to be dressed,and the reversing movement for the table will give a reliable andautomatic reciprocation of this table to move the work back and forthunder the wheels, and this movement will cooperate with the cams carriedbv the work support to properly present the work to the surface of thewheel. The hand lever 103 permits reversing of the table at any time,while placing of the block 82 in the intermediate position will stop thefeeding movements of the table. It will, of course, be understood thatthe construction and arrangement of the work support, the cams 52 andthe elements associated therewith may be varied considerably without6.0- parting from my invention. For example, the springs, the cams andthe levers 54 and 55 may be reversed and secure the same operation. Thiswould bring the cams on the under side of the support instead ofthe top.It is also to be understood that the term grinding wheel or abrasivewheel used in the specification and claims is used in the broad sense asindicating a grinding wheel, a polishing wheel or a bufling wheel.

Having thus set forth the nature of my 111- vention, what I claim is:

1. In a grinding and polishing machine. an abrasive wheel, a worksupport mounted for substantially universal movement including lateraland longitudinal rocking movements, means for shifting the support topresent the work to the wheel, and cam means for determining the heightand angular position of the support as it passes by the wheel.

2. In a grinding and polishing machine, a peripheral grinding wheel, awork support mounted for longitudinal movement past the Wheel and alsofor longitudinal and lateral rocking movements, cam elements on saidsupport, and means cooperating with said cam elements to determine theangular position of the support as it passes by the wheel.

3. In a grinding and polishing machine, a grinding wheel, a work supportmounted for up and down and lateral rocking movements, means for passingthe support by said wheel, cams carried by the support, and yieldablymounted means on opposite sides of the support engaging said cams andcooperating therewith during said movement to position said support.

4. In a grinding and polishing machine, a grinding wheel, a work supportmounted for up and down and rocking movements, means for passing thesupport by said wheel, cams carried by the support on opposite sides ofthe wheel, pivoted levers on opposite sides of the support, rollerscarried by the levers engaging said cams, and springs tending to holdthe rollers against the cams.

5. In a grinding and polishing machine, a grinding wheel, a. table, awork support mounted on the table for rocking movements, means forreciprocating said table to pass the support by the wheel, upright studson the table, springs on the studs for carrying the work support, camscarried by the support on opposite sides of the wheel, and yieldinglymounted rollers engaging said cams to determine the rocking movements ofthe support.

6. In a grinding and polishing machine, a peripheral grinding wheel, afloating work support mounted for up and down and lateral andlongitudinal rocking movements, means for passing the support by theperiphery of the wheel in substantially the plane of the wheel, a pairof cams carried by the support and extending longitudinally of thedirection of movement of the support, and means cooperating with thecams to determine the angular position of the support with respect tothe wheel.

7. In a grinding and polishing machine, a frame, an upright rotatableabrasive wheel, a table mounted on the frame below the wheel forlongitudinal reciprocating movements in the plane of the wheel, a worksup port mounted on the table and extending longitudinally thereof, saidsupport: being mounted for up and down movements and lateral andlongitudinal rocking movements, means on the support for holding thework to be operated upon, cams mounted on the support on opposite sidesof the work and extending longitudinally of the support, and separatemeans mounted on the frame cooperating with said cams as the supportreciprocates to determine the angular positions of the support.

8. In a grinding and polishing machine. a frame, an upright rotatableabrasive wheel, a table mounted on the frame below the wheel forlongitudinal reciprocating movements in the plane of the wheel, a worksupport mounted on the table for up and down and late :11 rockingmovements, means on the support for securing the work to be operatedupon, cams mounted on the support on opposite sides of the work andextending longitudinally of the support, levers pivotally mounted on theframe on opposite sides of the support, rollers carried by said leversand engaging said cams to cooperate therewith to determine the angularpositions of the support, and springs connected to the levers and actingto hold the rollers against the cams.

9. In a grinding and polishing machine, a frame, an upright rotatableabrasive Wheel, a table mounted on the frame below the Wheel forlongitudinal reciprocating movements in the plane of the Wheel, uprightguiding studs mounted on the table, a Work support loosely mounted onthe studs for up and down and lateral rocking movements, springs betweenthe table and the support to sustain the support, means on the supportfor retaining the work to be operated upon, a pair of cams mounted onthe support and arranged to rock the support in opposite directions, androllers mounted on the frame to engage said cams as the support isreciproeated.

In testimony whereof I affix my signature CHARLES Gr. JOHNSON.

